net/sched/act_api.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/act_api.c  Packet action API.
   4  *
   5  * Author:      Jamal Hadi Salim
   6  */
   7
   8 #include <linux/types.h>
   9 #include <linux/kernel.h>
  10 #include <linux/string.h>
  11 #include <linux/errno.h>
  12 #include <linux/slab.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/init.h>
  15 #include <linux/kmod.h>
  16 #include <linux/err.h>
  17 #include <linux/module.h>
  18 #include <net/net_namespace.h>
  19 #include <net/sock.h>
  20 #include <net/sch_generic.h>
  21 #include <net/pkt_cls.h>
  22 #include <net/act_api.h>
  23 #include <net/netlink.h>
  24
  25 static void tcf_action_goto_chain_exec(const struct tc_action *a,
  26                                        struct tcf_result *res)
  27 {
  28         const struct tcf_chain *chain = rcu_dereference_bh(a->goto_chain);
  29
  30         res->goto_tp = rcu_dereference_bh(chain->filter_chain);
  31 }
  32
  33 static void tcf_free_cookie_rcu(struct rcu_head *p)
  34 {
  35         struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
  36
  37         kfree(cookie->data);
  38         kfree(cookie);
  39 }
  40
  41 static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
  42                                   struct tc_cookie *new_cookie)
  43 {
  44         struct tc_cookie *old;
  45
  46         old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
  47         if (old)
  48                 call_rcu(&old->rcu, tcf_free_cookie_rcu);
  49 }
  50
  51 int tcf_action_check_ctrlact(int action, struct tcf_proto *tp,
  52                              struct tcf_chain **newchain,
  53                              struct netlink_ext_ack *extack)
  54 {
  55         int opcode = TC_ACT_EXT_OPCODE(action), ret = -EINVAL;
  56         u32 chain_index;
  57
  58         if (!opcode)
  59                 ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0;
  60         else if (opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC)
  61                 ret = 0;
  62         if (ret) {
  63                 NL_SET_ERR_MSG(extack, "invalid control action");
  64                 goto end;
  65         }
  66
  67         if (TC_ACT_EXT_CMP(action, TC_ACT_GOTO_CHAIN)) {
  68                 chain_index = action & TC_ACT_EXT_VAL_MASK;
  69                 if (!tp || !newchain) {
  70                         ret = -EINVAL;
  71                         NL_SET_ERR_MSG(extack,
  72                                        "can't goto NULL proto/chain");
  73                         goto end;
  74                 }
  75                 *newchain = tcf_chain_get_by_act(tp->chain->block, chain_index);
  76                 if (!*newchain) {
  77                         ret = -ENOMEM;
  78                         NL_SET_ERR_MSG(extack,
  79                                        "can't allocate goto_chain");
  80                 }
  81         }
  82 end:
  83         return ret;
  84 }
  85 EXPORT_SYMBOL(tcf_action_check_ctrlact);
  86
  87 struct tcf_chain *tcf_action_set_ctrlact(struct tc_action *a, int action,
  88                                          struct tcf_chain *goto_chain)
  89 {
  90         a->tcfa_action = action;
  91         goto_chain = rcu_replace_pointer(a->goto_chain, goto_chain, 1);
  92         return goto_chain;
  93 }
  94 EXPORT_SYMBOL(tcf_action_set_ctrlact);
  95
  96 /* XXX: For standalone actions, we don't need a RCU grace period either, because
  97  * actions are always connected to filters and filters are already destroyed in
  98  * RCU callbacks, so after a RCU grace period actions are already disconnected
  99  * from filters. Readers later can not find us.
 100  */
 101 static void free_tcf(struct tc_action *p)
 102 {
 103         struct tcf_chain *chain = rcu_dereference_protected(p->goto_chain, 1);
 104
 105         free_percpu(p->cpu_bstats);
 106         free_percpu(p->cpu_bstats_hw);
 107         free_percpu(p->cpu_qstats);
 108
 109         tcf_set_action_cookie(&p->act_cookie, NULL);
 110         if (chain)
 111                 tcf_chain_put_by_act(chain);
 112
 113         kfree(p);
 114 }
 115
 116 static void tcf_action_cleanup(struct tc_action *p)
 117 {
 118         if (p->ops->cleanup)
 119                 p->ops->cleanup(p);
 120
 121         gen_kill_estimator(&p->tcfa_rate_est);
 122         free_tcf(p);
 123 }
 124
 125 static int __tcf_action_put(struct tc_action *p, bool bind)
 126 {
 127         struct tcf_idrinfo *idrinfo = p->idrinfo;
 128
 129         if (refcount_dec_and_mutex_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
 130                 if (bind)
 131                         atomic_dec(&p->tcfa_bindcnt);
 132                 idr_remove(&idrinfo->action_idr, p->tcfa_index);
 133                 mutex_unlock(&idrinfo->lock);
 134
 135                 tcf_action_cleanup(p);
 136                 return 1;
 137         }
 138
 139         if (bind)
 140                 atomic_dec(&p->tcfa_bindcnt);
 141
 142         return 0;
 143 }
 144
 145 int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
 146 {
 147         int ret = 0;
 148
 149         /* Release with strict==1 and bind==0 is only called through act API
 150          * interface (classifiers always bind). Only case when action with
 151          * positive reference count and zero bind count can exist is when it was
 152          * also created with act API (unbinding last classifier will destroy the
 153          * action if it was created by classifier). So only case when bind count
 154          * can be changed after initial check is when unbound action is
 155          * destroyed by act API while classifier binds to action with same id
 156          * concurrently. This result either creation of new action(same behavior
 157          * as before), or reusing existing action if concurrent process
 158          * increments reference count before action is deleted. Both scenarios
 159          * are acceptable.
 160          */
 161         if (p) {
 162                 if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
 163                         return -EPERM;
 164
 165                 if (__tcf_action_put(p, bind))
 166                         ret = ACT_P_DELETED;
 167         }
 168
 169         return ret;
 170 }
 171 EXPORT_SYMBOL(__tcf_idr_release);
 172
 173 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
 174 {
 175         struct tc_cookie *act_cookie;
 176         u32 cookie_len = 0;
 177
 178         rcu_read_lock();
 179         act_cookie = rcu_dereference(act->act_cookie);
 180
 181         if (act_cookie)
 182                 cookie_len = nla_total_size(act_cookie->len);
 183         rcu_read_unlock();
 184
 185         return  nla_total_size(0) /* action number nested */
 186                 + nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
 187                 + cookie_len /* TCA_ACT_COOKIE */
 188                 + nla_total_size(0) /* TCA_ACT_STATS nested */
 189                 + nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_FLAGS */
 190                 /* TCA_STATS_BASIC */
 191                 + nla_total_size_64bit(sizeof(struct gnet_stats_basic))
 192                 /* TCA_STATS_PKT64 */
 193                 + nla_total_size_64bit(sizeof(u64))
 194                 /* TCA_STATS_QUEUE */
 195                 + nla_total_size_64bit(sizeof(struct gnet_stats_queue))
 196                 + nla_total_size(0) /* TCA_OPTIONS nested */
 197                 + nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
 198 }
 199
 200 static size_t tcf_action_full_attrs_size(size_t sz)
 201 {
 202         return NLMSG_HDRLEN                     /* struct nlmsghdr */
 203                 + sizeof(struct tcamsg)
 204                 + nla_total_size(0)             /* TCA_ACT_TAB nested */
 205                 + sz;
 206 }
 207
 208 static size_t tcf_action_fill_size(const struct tc_action *act)
 209 {
 210         size_t sz = tcf_action_shared_attrs_size(act);
 211
 212         if (act->ops->get_fill_size)
 213                 return act->ops->get_fill_size(act) + sz;
 214         return sz;
 215 }
 216
 217 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 218                            struct netlink_callback *cb)
 219 {
 220         int err = 0, index = -1, s_i = 0, n_i = 0;
 221         u32 act_flags = cb->args[2];
 222         unsigned long jiffy_since = cb->args[3];
 223         struct nlattr *nest;
 224         struct idr *idr = &idrinfo->action_idr;
 225         struct tc_action *p;
 226         unsigned long id = 1;
 227         unsigned long tmp;
 228
 229         mutex_lock(&idrinfo->lock);
 230
 231         s_i = cb->args[0];
 232
 233         idr_for_each_entry_ul(idr, p, tmp, id) {
 234                 index++;
 235                 if (index < s_i)
 236                         continue;
 237
 238                 if (jiffy_since &&
 239                     time_after(jiffy_since,
 240                                (unsigned long)p->tcfa_tm.lastuse))
 241                         continue;
 242
 243                 nest = nla_nest_start_noflag(skb, n_i);
 244                 if (!nest) {
 245                         index--;
 246                         goto nla_put_failure;
 247                 }
 248                 err = tcf_action_dump_1(skb, p, 0, 0);
 249                 if (err < 0) {
 250                         index--;
 251                         nlmsg_trim(skb, nest);
 252                         goto done;
 253                 }
 254                 nla_nest_end(skb, nest);
 255                 n_i++;
 256                 if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
 257                     n_i >= TCA_ACT_MAX_PRIO)
 258                         goto done;
 259         }
 260 done:
 261         if (index >= 0)
 262                 cb->args[0] = index + 1;
 263
 264         mutex_unlock(&idrinfo->lock);
 265         if (n_i) {
 266                 if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
 267                         cb->args[1] = n_i;
 268         }
 269         return n_i;
 270
 271 nla_put_failure:
 272         nla_nest_cancel(skb, nest);
 273         goto done;
 274 }
 275
 276 static int tcf_idr_release_unsafe(struct tc_action *p)
 277 {
 278         if (atomic_read(&p->tcfa_bindcnt) > 0)
 279                 return -EPERM;
 280
 281         if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 282                 idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
 283                 tcf_action_cleanup(p);
 284                 return ACT_P_DELETED;
 285         }
 286
 287         return 0;
 288 }
 289
 290 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 291                           const struct tc_action_ops *ops)
 292 {
 293         struct nlattr *nest;
 294         int n_i = 0;
 295         int ret = -EINVAL;
 296         struct idr *idr = &idrinfo->action_idr;
 297         struct tc_action *p;
 298         unsigned long id = 1;
 299         unsigned long tmp;
 300
 301         nest = nla_nest_start_noflag(skb, 0);
 302         if (nest == NULL)
 303                 goto nla_put_failure;
 304         if (nla_put_string(skb, TCA_KIND, ops->kind))
 305                 goto nla_put_failure;
 306
 307         mutex_lock(&idrinfo->lock);
 308         idr_for_each_entry_ul(idr, p, tmp, id) {
 309                 ret = tcf_idr_release_unsafe(p);
 310                 if (ret == ACT_P_DELETED) {
 311                         module_put(ops->owner);
 312                         n_i++;
 313                 } else if (ret < 0) {
 314                         mutex_unlock(&idrinfo->lock);
 315                         goto nla_put_failure;
 316                 }
 317         }
 318         mutex_unlock(&idrinfo->lock);
 319
 320         if (nla_put_u32(skb, TCA_FCNT, n_i))
 321                 goto nla_put_failure;
 322         nla_nest_end(skb, nest);
 323
 324         return n_i;
 325 nla_put_failure:
 326         nla_nest_cancel(skb, nest);
 327         return ret;
 328 }
 329
 330 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 331                        struct netlink_callback *cb, int type,
 332                        const struct tc_action_ops *ops,
 333                        struct netlink_ext_ack *extack)
 334 {
 335         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 336
 337         if (type == RTM_DELACTION) {
 338                 return tcf_del_walker(idrinfo, skb, ops);
 339         } else if (type == RTM_GETACTION) {
 340                 return tcf_dump_walker(idrinfo, skb, cb);
 341         } else {
 342                 WARN(1, "tcf_generic_walker: unknown command %d\n", type);
 343                 NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
 344                 return -EINVAL;
 345         }
 346 }
 347 EXPORT_SYMBOL(tcf_generic_walker);
 348
 349 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
 350 {
 351         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 352         struct tc_action *p;
 353
 354         mutex_lock(&idrinfo->lock);
 355         p = idr_find(&idrinfo->action_idr, index);
 356         if (IS_ERR(p))
 357                 p = NULL;
 358         else if (p)
 359                 refcount_inc(&p->tcfa_refcnt);
 360         mutex_unlock(&idrinfo->lock);
 361
 362         if (p) {
 363                 *a = p;
 364                 return true;
 365         }
 366         return false;
 367 }
 368 EXPORT_SYMBOL(tcf_idr_search);
 369
 370 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
 371 {
 372         struct tc_action *p;
 373         int ret = 0;
 374
 375         mutex_lock(&idrinfo->lock);
 376         p = idr_find(&idrinfo->action_idr, index);
 377         if (!p) {
 378                 mutex_unlock(&idrinfo->lock);
 379                 return -ENOENT;
 380         }
 381
 382         if (!atomic_read(&p->tcfa_bindcnt)) {
 383                 if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 384                         struct module *owner = p->ops->owner;
 385
 386                         WARN_ON(p != idr_remove(&idrinfo->action_idr,
 387                                                 p->tcfa_index));
 388                         mutex_unlock(&idrinfo->lock);
 389
 390                         tcf_action_cleanup(p);
 391                         module_put(owner);
 392                         return 0;
 393                 }
 394                 ret = 0;
 395         } else {
 396                 ret = -EPERM;
 397         }
 398
 399         mutex_unlock(&idrinfo->lock);
 400         return ret;
 401 }
 402
 403 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 404                    struct tc_action **a, const struct tc_action_ops *ops,
 405                    int bind, bool cpustats, u32 flags)
 406 {
 407         struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
 408         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 409         int err = -ENOMEM;
 410
 411         if (unlikely(!p))
 412                 return -ENOMEM;
 413         refcount_set(&p->tcfa_refcnt, 1);
 414         if (bind)
 415                 atomic_set(&p->tcfa_bindcnt, 1);
 416
 417         if (cpustats) {
 418                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 419                 if (!p->cpu_bstats)
 420                         goto err1;
 421                 p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 422                 if (!p->cpu_bstats_hw)
 423                         goto err2;
 424                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 425                 if (!p->cpu_qstats)
 426                         goto err3;
 427         }
 428         spin_lock_init(&p->tcfa_lock);
 429         p->tcfa_index = index;
 430         p->tcfa_tm.install = jiffies;
 431         p->tcfa_tm.lastuse = jiffies;
 432         p->tcfa_tm.firstuse = 0;
 433         p->tcfa_flags = flags;
 434         if (est) {
 435                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 436                                         &p->tcfa_rate_est,
 437                                         &p->tcfa_lock, NULL, est);
 438                 if (err)
 439                         goto err4;
 440         }
 441
 442         p->idrinfo = idrinfo;
 443         p->ops = ops;
 444         *a = p;
 445         return 0;
 446 err4:
 447         free_percpu(p->cpu_qstats);
 448 err3:
 449         free_percpu(p->cpu_bstats_hw);
 450 err2:
 451         free_percpu(p->cpu_bstats);
 452 err1:
 453         kfree(p);
 454         return err;
 455 }
 456 EXPORT_SYMBOL(tcf_idr_create);
 457
 458 int tcf_idr_create_from_flags(struct tc_action_net *tn, u32 index,
 459                               struct nlattr *est, struct tc_action **a,
 460                               const struct tc_action_ops *ops, int bind,
 461                               u32 flags)
 462 {
 463         /* Set cpustats according to actions flags. */
 464         return tcf_idr_create(tn, index, est, a, ops, bind,
 465                               !(flags & TCA_ACT_FLAGS_NO_PERCPU_STATS), flags);
 466 }
 467 EXPORT_SYMBOL(tcf_idr_create_from_flags);
 468
 469 void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
 470 {
 471         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 472
 473         mutex_lock(&idrinfo->lock);
 474         /* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 475         WARN_ON(!IS_ERR(idr_replace(&idrinfo->action_idr, a, a->tcfa_index)));
 476         mutex_unlock(&idrinfo->lock);
 477 }
 478 EXPORT_SYMBOL(tcf_idr_insert);
 479
 480 /* Cleanup idr index that was allocated but not initialized. */
 481
 482 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
 483 {
 484         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 485
 486         mutex_lock(&idrinfo->lock);
 487         /* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 488         WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
 489         mutex_unlock(&idrinfo->lock);
 490 }
 491 EXPORT_SYMBOL(tcf_idr_cleanup);
 492
 493 /* Check if action with specified index exists. If actions is found, increments
 494  * its reference and bind counters, and return 1. Otherwise insert temporary
 495  * error pointer (to prevent concurrent users from inserting actions with same
 496  * index) and return 0.
 497  */
 498
 499 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
 500                         struct tc_action **a, int bind)
 501 {
 502         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 503         struct tc_action *p;
 504         int ret;
 505
 506 again:
 507         mutex_lock(&idrinfo->lock);
 508         if (*index) {
 509                 p = idr_find(&idrinfo->action_idr, *index);
 510                 if (IS_ERR(p)) {
 511                         /* This means that another process allocated
 512                          * index but did not assign the pointer yet.
 513                          */
 514                         mutex_unlock(&idrinfo->lock);
 515                         goto again;
 516                 }
 517
 518                 if (p) {
 519                         refcount_inc(&p->tcfa_refcnt);
 520                         if (bind)
 521                                 atomic_inc(&p->tcfa_bindcnt);
 522                         *a = p;
 523                         ret = 1;
 524                 } else {
 525                         *a = NULL;
 526                         ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 527                                             *index, GFP_KERNEL);
 528                         if (!ret)
 529                                 idr_replace(&idrinfo->action_idr,
 530                                             ERR_PTR(-EBUSY), *index);
 531                 }
 532         } else {
 533                 *index = 1;
 534                 *a = NULL;
 535                 ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 536                                     UINT_MAX, GFP_KERNEL);
 537                 if (!ret)
 538                         idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
 539                                     *index);
 540         }
 541         mutex_unlock(&idrinfo->lock);
 542         return ret;
 543 }
 544 EXPORT_SYMBOL(tcf_idr_check_alloc);
 545
 546 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
 547                          struct tcf_idrinfo *idrinfo)
 548 {
 549         struct idr *idr = &idrinfo->action_idr;
 550         struct tc_action *p;
 551         int ret;
 552         unsigned long id = 1;
 553         unsigned long tmp;
 554
 555         idr_for_each_entry_ul(idr, p, tmp, id) {
 556                 ret = __tcf_idr_release(p, false, true);
 557                 if (ret == ACT_P_DELETED)
 558                         module_put(ops->owner);
 559                 else if (ret < 0)
 560                         return;
 561         }
 562         idr_destroy(&idrinfo->action_idr);
 563 }
 564 EXPORT_SYMBOL(tcf_idrinfo_destroy);
 565
 566 static LIST_HEAD(act_base);
 567 static DEFINE_RWLOCK(act_mod_lock);
 568
 569 int tcf_register_action(struct tc_action_ops *act,
 570                         struct pernet_operations *ops)
 571 {
 572         struct tc_action_ops *a;
 573         int ret;
 574
 575         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 576                 return -EINVAL;
 577
 578         /* We have to register pernet ops before making the action ops visible,
 579          * otherwise tcf_action_init_1() could get a partially initialized
 580          * netns.
 581          */
 582         ret = register_pernet_subsys(ops);
 583         if (ret)
 584                 return ret;
 585
 586         write_lock(&act_mod_lock);
 587         list_for_each_entry(a, &act_base, head) {
 588                 if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
 589                         write_unlock(&act_mod_lock);
 590                         unregister_pernet_subsys(ops);
 591                         return -EEXIST;
 592                 }
 593         }
 594         list_add_tail(&act->head, &act_base);
 595         write_unlock(&act_mod_lock);
 596
 597         return 0;
 598 }
 599 EXPORT_SYMBOL(tcf_register_action);
 600
 601 int tcf_unregister_action(struct tc_action_ops *act,
 602                           struct pernet_operations *ops)
 603 {
 604         struct tc_action_ops *a;
 605         int err = -ENOENT;
 606
 607         write_lock(&act_mod_lock);
 608         list_for_each_entry(a, &act_base, head) {
 609                 if (a == act) {
 610                         list_del(&act->head);
 611                         err = 0;
 612                         break;
 613                 }
 614         }
 615         write_unlock(&act_mod_lock);
 616         if (!err)
 617                 unregister_pernet_subsys(ops);
 618         return err;
 619 }
 620 EXPORT_SYMBOL(tcf_unregister_action);
 621
 622 /* lookup by name */
 623 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 624 {
 625         struct tc_action_ops *a, *res = NULL;
 626
 627         if (kind) {
 628                 read_lock(&act_mod_lock);
 629                 list_for_each_entry(a, &act_base, head) {
 630                         if (strcmp(kind, a->kind) == 0) {
 631                                 if (try_module_get(a->owner))
 632                                         res = a;
 633                                 break;
 634                         }
 635                 }
 636                 read_unlock(&act_mod_lock);
 637         }
 638         return res;
 639 }
 640
 641 /* lookup by nlattr */
 642 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 643 {
 644         struct tc_action_ops *a, *res = NULL;
 645
 646         if (kind) {
 647                 read_lock(&act_mod_lock);
 648                 list_for_each_entry(a, &act_base, head) {
 649                         if (nla_strcmp(kind, a->kind) == 0) {
 650                                 if (try_module_get(a->owner))
 651                                         res = a;
 652                                 break;
 653                         }
 654                 }
 655                 read_unlock(&act_mod_lock);
 656         }
 657         return res;
 658 }
 659
 660 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
 661 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
 662 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 663                     int nr_actions, struct tcf_result *res)
 664 {
 665         u32 jmp_prgcnt = 0;
 666         u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
 667         int i;
 668         int ret = TC_ACT_OK;
 669
 670         if (skb_skip_tc_classify(skb))
 671                 return TC_ACT_OK;
 672
 673 restart_act_graph:
 674         for (i = 0; i < nr_actions; i++) {
 675                 const struct tc_action *a = actions[i];
 676
 677                 if (jmp_prgcnt > 0) {
 678                         jmp_prgcnt -= 1;
 679                         continue;
 680                 }
 681 repeat:
 682                 ret = a->ops->act(skb, a, res);
 683                 if (ret == TC_ACT_REPEAT)
 684                         goto repeat;    /* we need a ttl - JHS */
 685
 686                 if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
 687                         jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
 688                         if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
 689                                 /* faulty opcode, stop pipeline */
 690                                 return TC_ACT_OK;
 691                         } else {
 692                                 jmp_ttl -= 1;
 693                                 if (jmp_ttl > 0)
 694                                         goto restart_act_graph;
 695                                 else /* faulty graph, stop pipeline */
 696                                         return TC_ACT_OK;
 697                         }
 698                 } else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
 699                         if (unlikely(!rcu_access_pointer(a->goto_chain))) {
 700                                 net_warn_ratelimited("can't go to NULL chain!\n");
 701                                 return TC_ACT_SHOT;
 702                         }
 703                         tcf_action_goto_chain_exec(a, res);
 704                 }
 705
 706                 if (ret != TC_ACT_PIPE)
 707                         break;
 708         }
 709
 710         return ret;
 711 }
 712 EXPORT_SYMBOL(tcf_action_exec);
 713
 714 int tcf_action_destroy(struct tc_action *actions[], int bind)
 715 {
 716         const struct tc_action_ops *ops;
 717         struct tc_action *a;
 718         int ret = 0, i;
 719
 720         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 721                 a = actions[i];
 722                 actions[i] = NULL;
 723                 ops = a->ops;
 724                 ret = __tcf_idr_release(a, bind, true);
 725                 if (ret == ACT_P_DELETED)
 726                         module_put(ops->owner);
 727                 else if (ret < 0)
 728                         return ret;
 729         }
 730         return ret;
 731 }
 732
 733 static int tcf_action_destroy_1(struct tc_action *a, int bind)
 734 {
 735         struct tc_action *actions[] = { a, NULL };
 736
 737         return tcf_action_destroy(actions, bind);
 738 }
 739
 740 static int tcf_action_put(struct tc_action *p)
 741 {
 742         return __tcf_action_put(p, false);
 743 }
 744
 745 /* Put all actions in this array, skip those NULL's. */
 746 static void tcf_action_put_many(struct tc_action *actions[])
 747 {
 748         int i;
 749
 750         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 751                 struct tc_action *a = actions[i];
 752                 const struct tc_action_ops *ops;
 753
 754                 if (!a)
 755                         continue;
 756                 ops = a->ops;
 757                 if (tcf_action_put(a))
 758                         module_put(ops->owner);
 759         }
 760 }
 761
 762 int
 763 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 764 {
 765         return a->ops->dump(skb, a, bind, ref);
 766 }
 767
 768 int
 769 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 770 {
 771         int err = -EINVAL;
 772         unsigned char *b = skb_tail_pointer(skb);
 773         struct nlattr *nest;
 774         struct tc_cookie *cookie;
 775
 776         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 777                 goto nla_put_failure;
 778         if (tcf_action_copy_stats(skb, a, 0))
 779                 goto nla_put_failure;
 780
 781         rcu_read_lock();
 782         cookie = rcu_dereference(a->act_cookie);
 783         if (cookie) {
 784                 if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
 785                         rcu_read_unlock();
 786                         goto nla_put_failure;
 787                 }
 788         }
 789         rcu_read_unlock();
 790
 791         if (a->tcfa_flags) {
 792                 struct nla_bitfield32 flags = { a->tcfa_flags,
 793                                                 a->tcfa_flags, };
 794
 795                 if (nla_put(skb, TCA_ACT_FLAGS, sizeof(flags), &flags))
 796                         goto nla_put_failure;
 797         }
 798
 799         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 800         if (nest == NULL)
 801                 goto nla_put_failure;
 802         err = tcf_action_dump_old(skb, a, bind, ref);
 803         if (err > 0) {
 804                 nla_nest_end(skb, nest);
 805                 return err;
 806         }
 807
 808 nla_put_failure:
 809         nlmsg_trim(skb, b);
 810         return -1;
 811 }
 812 EXPORT_SYMBOL(tcf_action_dump_1);
 813
 814 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
 815                     int bind, int ref)
 816 {
 817         struct tc_action *a;
 818         int err = -EINVAL, i;
 819         struct nlattr *nest;
 820
 821         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 822                 a = actions[i];
 823                 nest = nla_nest_start_noflag(skb, i + 1);
 824                 if (nest == NULL)
 825                         goto nla_put_failure;
 826                 err = tcf_action_dump_1(skb, a, bind, ref);
 827                 if (err < 0)
 828                         goto errout;
 829                 nla_nest_end(skb, nest);
 830         }
 831
 832         return 0;
 833
 834 nla_put_failure:
 835         err = -EINVAL;
 836 errout:
 837         nla_nest_cancel(skb, nest);
 838         return err;
 839 }
 840
 841 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 842 {
 843         struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
 844         if (!c)
 845                 return NULL;
 846
 847         c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
 848         if (!c->data) {
 849                 kfree(c);
 850                 return NULL;
 851         }
 852         c->len = nla_len(tb[TCA_ACT_COOKIE]);
 853
 854         return c;
 855 }
 856
 857 static const u32 tca_act_flags_allowed = TCA_ACT_FLAGS_NO_PERCPU_STATS;
 858 static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = {
 859         [TCA_ACT_KIND]          = { .type = NLA_STRING },
 860         [TCA_ACT_INDEX]         = { .type = NLA_U32 },
 861         [TCA_ACT_COOKIE]        = { .type = NLA_BINARY,
 862                                     .len = TC_COOKIE_MAX_SIZE },
 863         [TCA_ACT_OPTIONS]       = { .type = NLA_NESTED },
 864         [TCA_ACT_FLAGS]         = { .type = NLA_BITFIELD32,
 865                                     .validation_data = &tca_act_flags_allowed },
 866 };
 867
 868 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 869                                     struct nlattr *nla, struct nlattr *est,
 870                                     char *name, int ovr, int bind,
 871                                     bool rtnl_held,
 872                                     struct netlink_ext_ack *extack)
 873 {
 874         struct nla_bitfield32 flags = { 0, 0 };
 875         struct tc_action *a;
 876         struct tc_action_ops *a_o;
 877         struct tc_cookie *cookie = NULL;
 878         char act_name[IFNAMSIZ];
 879         struct nlattr *tb[TCA_ACT_MAX + 1];
 880         struct nlattr *kind;
 881         int err;
 882
 883         if (name == NULL) {
 884                 err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
 885                                                   tcf_action_policy, extack);
 886                 if (err < 0)
 887                         goto err_out;
 888                 err = -EINVAL;
 889                 kind = tb[TCA_ACT_KIND];
 890                 if (!kind) {
 891                         NL_SET_ERR_MSG(extack, "TC action kind must be specified");
 892                         goto err_out;
 893                 }
 894                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
 895                         NL_SET_ERR_MSG(extack, "TC action name too long");
 896                         goto err_out;
 897                 }
 898                 if (tb[TCA_ACT_COOKIE]) {
 899                         cookie = nla_memdup_cookie(tb);
 900                         if (!cookie) {
 901                                 NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
 902                                 err = -ENOMEM;
 903                                 goto err_out;
 904                         }
 905                 }
 906                 if (tb[TCA_ACT_FLAGS])
 907                         flags = nla_get_bitfield32(tb[TCA_ACT_FLAGS]);
 908         } else {
 909                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
 910                         NL_SET_ERR_MSG(extack, "TC action name too long");
 911                         err = -EINVAL;
 912                         goto err_out;
 913                 }
 914         }
 915
 916         a_o = tc_lookup_action_n(act_name);
 917         if (a_o == NULL) {
 918 #ifdef CONFIG_MODULES
 919                 if (rtnl_held)
 920                         rtnl_unlock();
 921                 request_module("act_%s", act_name);
 922                 if (rtnl_held)
 923                         rtnl_lock();
 924
 925                 a_o = tc_lookup_action_n(act_name);
 926
 927                 /* We dropped the RTNL semaphore in order to
 928                  * perform the module load.  So, even if we
 929                  * succeeded in loading the module we have to
 930                  * tell the caller to replay the request.  We
 931                  * indicate this using -EAGAIN.
 932                  */
 933                 if (a_o != NULL) {
 934                         err = -EAGAIN;
 935                         goto err_mod;
 936                 }
 937 #endif
 938                 NL_SET_ERR_MSG(extack, "Failed to load TC action module");
 939                 err = -ENOENT;
 940                 goto err_out;
 941         }
 942
 943         /* backward compatibility for policer */
 944         if (name == NULL)
 945                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
 946                                 rtnl_held, tp, flags.value, extack);
 947         else
 948                 err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
 949                                 tp, flags.value, extack);
 950         if (err < 0)
 951                 goto err_mod;
 952
 953         if (!name && tb[TCA_ACT_COOKIE])
 954                 tcf_set_action_cookie(&a->act_cookie, cookie);
 955
 956         /* module count goes up only when brand new policy is created
 957          * if it exists and is only bound to in a_o->init() then
 958          * ACT_P_CREATED is not returned (a zero is).
 959          */
 960         if (err != ACT_P_CREATED)
 961                 module_put(a_o->owner);
 962
 963         if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN) &&
 964             !rcu_access_pointer(a->goto_chain)) {
 965                 tcf_action_destroy_1(a, bind);
 966                 NL_SET_ERR_MSG(extack, "can't use goto chain with NULL chain");
 967                 return ERR_PTR(-EINVAL);
 968         }
 969
 970         return a;
 971
 972 err_mod:
 973         module_put(a_o->owner);
 974 err_out:
 975         if (cookie) {
 976                 kfree(cookie->data);
 977                 kfree(cookie);
 978         }
 979         return ERR_PTR(err);
 980 }
 981
 982 /* Returns numbers of initialized actions or negative error. */
 983
 984 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
 985                     struct nlattr *est, char *name, int ovr, int bind,
 986                     struct tc_action *actions[], size_t *attr_size,
 987                     bool rtnl_held, struct netlink_ext_ack *extack)
 988 {
 989         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 990         struct tc_action *act;
 991         size_t sz = 0;
 992         int err;
 993         int i;
 994
 995         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
 996                                           extack);
 997         if (err < 0)
 998                 return err;
 999
1000         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1001                 act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
1002                                         rtnl_held, extack);
1003                 if (IS_ERR(act)) {
1004                         err = PTR_ERR(act);
1005                         goto err;
1006                 }
1007                 sz += tcf_action_fill_size(act);
1008                 /* Start from index 0 */
1009                 actions[i - 1] = act;
1010         }
1011
1012         *attr_size = tcf_action_full_attrs_size(sz);
1013         return i - 1;
1014
1015 err:
1016         tcf_action_destroy(actions, bind);
1017         return err;
1018 }
1019
1020 void tcf_action_update_stats(struct tc_action *a, u64 bytes, u32 packets,
1021                              bool drop, bool hw)
1022 {
1023         if (a->cpu_bstats) {
1024                 _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
1025
1026                 if (drop)
1027                         this_cpu_ptr(a->cpu_qstats)->drops += packets;
1028
1029                 if (hw)
1030                         _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
1031                                            bytes, packets);
1032                 return;
1033         }
1034
1035         _bstats_update(&a->tcfa_bstats, bytes, packets);
1036         if (drop)
1037                 a->tcfa_qstats.drops += packets;
1038         if (hw)
1039                 _bstats_update(&a->tcfa_bstats_hw, bytes, packets);
1040 }
1041 EXPORT_SYMBOL(tcf_action_update_stats);
1042
1043 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
1044                           int compat_mode)
1045 {
1046         int err = 0;
1047         struct gnet_dump d;
1048
1049         if (p == NULL)
1050                 goto errout;
1051
1052         /* compat_mode being true specifies a call that is supposed
1053          * to add additional backward compatibility statistic TLVs.
1054          */
1055         if (compat_mode) {
1056                 if (p->type == TCA_OLD_COMPAT)
1057                         err = gnet_stats_start_copy_compat(skb, 0,
1058                                                            TCA_STATS,
1059                                                            TCA_XSTATS,
1060                                                            &p->tcfa_lock, &d,
1061                                                            TCA_PAD);
1062                 else
1063                         return 0;
1064         } else
1065                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
1066                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
1067
1068         if (err < 0)
1069                 goto errout;
1070
1071         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
1072             gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
1073                                      &p->tcfa_bstats_hw) < 0 ||
1074             gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1075             gnet_stats_copy_queue(&d, p->cpu_qstats,
1076                                   &p->tcfa_qstats,
1077                                   p->tcfa_qstats.qlen) < 0)
1078                 goto errout;
1079
1080         if (gnet_stats_finish_copy(&d) < 0)
1081                 goto errout;
1082
1083         return 0;
1084
1085 errout:
1086         return -1;
1087 }
1088
1089 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1090                         u32 portid, u32 seq, u16 flags, int event, int bind,
1091                         int ref)
1092 {
1093         struct tcamsg *t;
1094         struct nlmsghdr *nlh;
1095         unsigned char *b = skb_tail_pointer(skb);
1096         struct nlattr *nest;
1097
1098         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1099         if (!nlh)
1100                 goto out_nlmsg_trim;
1101         t = nlmsg_data(nlh);
1102         t->tca_family = AF_UNSPEC;
1103         t->tca__pad1 = 0;
1104         t->tca__pad2 = 0;
1105
1106         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1107         if (!nest)
1108                 goto out_nlmsg_trim;
1109
1110         if (tcf_action_dump(skb, actions, bind, ref) < 0)
1111                 goto out_nlmsg_trim;
1112
1113         nla_nest_end(skb, nest);
1114
1115         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1116         return skb->len;
1117
1118 out_nlmsg_trim:
1119         nlmsg_trim(skb, b);
1120         return -1;
1121 }
1122
1123 static int
1124 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1125                struct tc_action *actions[], int event,
1126                struct netlink_ext_ack *extack)
1127 {
1128         struct sk_buff *skb;
1129
1130         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1131         if (!skb)
1132                 return -ENOBUFS;
1133         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1134                          0, 1) <= 0) {
1135                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1136                 kfree_skb(skb);
1137                 return -EINVAL;
1138         }
1139
1140         return rtnl_unicast(skb, net, portid);
1141 }
1142
1143 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1144                                           struct nlmsghdr *n, u32 portid,
1145                                           struct netlink_ext_ack *extack)
1146 {
1147         struct nlattr *tb[TCA_ACT_MAX + 1];
1148         const struct tc_action_ops *ops;
1149         struct tc_action *a;
1150         int index;
1151         int err;
1152
1153         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1154                                           tcf_action_policy, extack);
1155         if (err < 0)
1156                 goto err_out;
1157
1158         err = -EINVAL;
1159         if (tb[TCA_ACT_INDEX] == NULL ||
1160             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1161                 NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1162                 goto err_out;
1163         }
1164         index = nla_get_u32(tb[TCA_ACT_INDEX]);
1165
1166         err = -EINVAL;
1167         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1168         if (!ops) { /* could happen in batch of actions */
1169                 NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1170                 goto err_out;
1171         }
1172         err = -ENOENT;
1173         if (ops->lookup(net, &a, index) == 0) {
1174                 NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1175                 goto err_mod;
1176         }
1177
1178         module_put(ops->owner);
1179         return a;
1180
1181 err_mod:
1182         module_put(ops->owner);
1183 err_out:
1184         return ERR_PTR(err);
1185 }
1186
1187 static int tca_action_flush(struct net *net, struct nlattr *nla,
1188                             struct nlmsghdr *n, u32 portid,
1189                             struct netlink_ext_ack *extack)
1190 {
1191         struct sk_buff *skb;
1192         unsigned char *b;
1193         struct nlmsghdr *nlh;
1194         struct tcamsg *t;
1195         struct netlink_callback dcb;
1196         struct nlattr *nest;
1197         struct nlattr *tb[TCA_ACT_MAX + 1];
1198         const struct tc_action_ops *ops;
1199         struct nlattr *kind;
1200         int err = -ENOMEM;
1201
1202         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1203         if (!skb)
1204                 return err;
1205
1206         b = skb_tail_pointer(skb);
1207
1208         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1209                                           tcf_action_policy, extack);
1210         if (err < 0)
1211                 goto err_out;
1212
1213         err = -EINVAL;
1214         kind = tb[TCA_ACT_KIND];
1215         ops = tc_lookup_action(kind);
1216         if (!ops) { /*some idjot trying to flush unknown action */
1217                 NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1218                 goto err_out;
1219         }
1220
1221         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1222                         sizeof(*t), 0);
1223         if (!nlh) {
1224                 NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1225                 goto out_module_put;
1226         }
1227         t = nlmsg_data(nlh);
1228         t->tca_family = AF_UNSPEC;
1229         t->tca__pad1 = 0;
1230         t->tca__pad2 = 0;
1231
1232         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1233         if (!nest) {
1234                 NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1235                 goto out_module_put;
1236         }
1237
1238         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1239         if (err <= 0) {
1240                 nla_nest_cancel(skb, nest);
1241                 goto out_module_put;
1242         }
1243
1244         nla_nest_end(skb, nest);
1245
1246         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1247         nlh->nlmsg_flags |= NLM_F_ROOT;
1248         module_put(ops->owner);
1249         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1250                              n->nlmsg_flags & NLM_F_ECHO);
1251         if (err > 0)
1252                 return 0;
1253         if (err < 0)
1254                 NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1255
1256         return err;
1257
1258 out_module_put:
1259         module_put(ops->owner);
1260 err_out:
1261         kfree_skb(skb);
1262         return err;
1263 }
1264
1265 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1266 {
1267         int i;
1268
1269         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1270                 struct tc_action *a = actions[i];
1271                 const struct tc_action_ops *ops = a->ops;
1272                 /* Actions can be deleted concurrently so we must save their
1273                  * type and id to search again after reference is released.
1274                  */
1275                 struct tcf_idrinfo *idrinfo = a->idrinfo;
1276                 u32 act_index = a->tcfa_index;
1277
1278                 actions[i] = NULL;
1279                 if (tcf_action_put(a)) {
1280                         /* last reference, action was deleted concurrently */
1281                         module_put(ops->owner);
1282                 } else  {
1283                         int ret;
1284
1285                         /* now do the delete */
1286                         ret = tcf_idr_delete_index(idrinfo, act_index);
1287                         if (ret < 0)
1288                                 return ret;
1289                 }
1290         }
1291         return 0;
1292 }
1293
1294 static int
1295 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1296                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1297 {
1298         int ret;
1299         struct sk_buff *skb;
1300
1301         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1302                         GFP_KERNEL);
1303         if (!skb)
1304                 return -ENOBUFS;
1305
1306         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1307                          0, 2) <= 0) {
1308                 NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1309                 kfree_skb(skb);
1310                 return -EINVAL;
1311         }
1312
1313         /* now do the delete */
1314         ret = tcf_action_delete(net, actions);
1315         if (ret < 0) {
1316                 NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1317                 kfree_skb(skb);
1318                 return ret;
1319         }
1320
1321         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1322                              n->nlmsg_flags & NLM_F_ECHO);
1323         if (ret > 0)
1324                 return 0;
1325         return ret;
1326 }
1327
1328 static int
1329 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1330               u32 portid, int event, struct netlink_ext_ack *extack)
1331 {
1332         int i, ret;
1333         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1334         struct tc_action *act;
1335         size_t attr_size = 0;
1336         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1337
1338         ret = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1339                                           extack);
1340         if (ret < 0)
1341                 return ret;
1342
1343         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1344                 if (tb[1])
1345                         return tca_action_flush(net, tb[1], n, portid, extack);
1346
1347                 NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1348                 return -EINVAL;
1349         }
1350
1351         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1352                 act = tcf_action_get_1(net, tb[i], n, portid, extack);
1353                 if (IS_ERR(act)) {
1354                         ret = PTR_ERR(act);
1355                         goto err;
1356                 }
1357                 attr_size += tcf_action_fill_size(act);
1358                 actions[i - 1] = act;
1359         }
1360
1361         attr_size = tcf_action_full_attrs_size(attr_size);
1362
1363         if (event == RTM_GETACTION)
1364                 ret = tcf_get_notify(net, portid, n, actions, event, extack);
1365         else { /* delete */
1366                 ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1367                 if (ret)
1368                         goto err;
1369                 return 0;
1370         }
1371 err:
1372         tcf_action_put_many(actions);
1373         return ret;
1374 }
1375
1376 static int
1377 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1378                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1379 {
1380         struct sk_buff *skb;
1381         int err = 0;
1382
1383         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1384                         GFP_KERNEL);
1385         if (!skb)
1386                 return -ENOBUFS;
1387
1388         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1389                          RTM_NEWACTION, 0, 0) <= 0) {
1390                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1391                 kfree_skb(skb);
1392                 return -EINVAL;
1393         }
1394
1395         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1396                              n->nlmsg_flags & NLM_F_ECHO);
1397         if (err > 0)
1398                 err = 0;
1399         return err;
1400 }
1401
1402 static int tcf_action_add(struct net *net, struct nlattr *nla,
1403                           struct nlmsghdr *n, u32 portid, int ovr,
1404                           struct netlink_ext_ack *extack)
1405 {
1406         size_t attr_size = 0;
1407         int loop, ret;
1408         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1409
1410         for (loop = 0; loop < 10; loop++) {
1411                 ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0,
1412                                       actions, &attr_size, true, extack);
1413                 if (ret != -EAGAIN)
1414                         break;
1415         }
1416
1417         if (ret < 0)
1418                 return ret;
1419         ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1420         if (ovr)
1421                 tcf_action_put_many(actions);
1422
1423         return ret;
1424 }
1425
1426 static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON;
1427 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1428         [TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32,
1429                              .validation_data = &tcaa_root_flags_allowed },
1430         [TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1431 };
1432
1433 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1434                          struct netlink_ext_ack *extack)
1435 {
1436         struct net *net = sock_net(skb->sk);
1437         struct nlattr *tca[TCA_ROOT_MAX + 1];
1438         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1439         int ret = 0, ovr = 0;
1440
1441         if ((n->nlmsg_type != RTM_GETACTION) &&
1442             !netlink_capable(skb, CAP_NET_ADMIN))
1443                 return -EPERM;
1444
1445         ret = nlmsg_parse_deprecated(n, sizeof(struct tcamsg), tca,
1446                                      TCA_ROOT_MAX, NULL, extack);
1447         if (ret < 0)
1448                 return ret;
1449
1450         if (tca[TCA_ACT_TAB] == NULL) {
1451                 NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1452                 return -EINVAL;
1453         }
1454
1455         /* n->nlmsg_flags & NLM_F_CREATE */
1456         switch (n->nlmsg_type) {
1457         case RTM_NEWACTION:
1458                 /* we are going to assume all other flags
1459                  * imply create only if it doesn't exist
1460                  * Note that CREATE | EXCL implies that
1461                  * but since we want avoid ambiguity (eg when flags
1462                  * is zero) then just set this
1463                  */
1464                 if (n->nlmsg_flags & NLM_F_REPLACE)
1465                         ovr = 1;
1466                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1467                                      extack);
1468                 break;
1469         case RTM_DELACTION:
1470                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1471                                     portid, RTM_DELACTION, extack);
1472                 break;
1473         case RTM_GETACTION:
1474                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1475                                     portid, RTM_GETACTION, extack);
1476                 break;
1477         default:
1478                 BUG();
1479         }
1480
1481         return ret;
1482 }
1483
1484 static struct nlattr *find_dump_kind(struct nlattr **nla)
1485 {
1486         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1487         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1488         struct nlattr *kind;
1489
1490         tb1 = nla[TCA_ACT_TAB];
1491         if (tb1 == NULL)
1492                 return NULL;
1493
1494         if (nla_parse_deprecated(tb, TCA_ACT_MAX_PRIO, nla_data(tb1), NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1495                 return NULL;
1496
1497         if (tb[1] == NULL)
1498                 return NULL;
1499         if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], tcf_action_policy, NULL) < 0)
1500                 return NULL;
1501         kind = tb2[TCA_ACT_KIND];
1502
1503         return kind;
1504 }
1505
1506 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1507 {
1508         struct net *net = sock_net(skb->sk);
1509         struct nlmsghdr *nlh;
1510         unsigned char *b = skb_tail_pointer(skb);
1511         struct nlattr *nest;
1512         struct tc_action_ops *a_o;
1513         int ret = 0;
1514         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1515         struct nlattr *tb[TCA_ROOT_MAX + 1];
1516         struct nlattr *count_attr = NULL;
1517         unsigned long jiffy_since = 0;
1518         struct nlattr *kind = NULL;
1519         struct nla_bitfield32 bf;
1520         u32 msecs_since = 0;
1521         u32 act_count = 0;
1522
1523         ret = nlmsg_parse_deprecated(cb->nlh, sizeof(struct tcamsg), tb,
1524                                      TCA_ROOT_MAX, tcaa_policy, cb->extack);
1525         if (ret < 0)
1526                 return ret;
1527
1528         kind = find_dump_kind(tb);
1529         if (kind == NULL) {
1530                 pr_info("tc_dump_action: action bad kind\n");
1531                 return 0;
1532         }
1533
1534         a_o = tc_lookup_action(kind);
1535         if (a_o == NULL)
1536                 return 0;
1537
1538         cb->args[2] = 0;
1539         if (tb[TCA_ROOT_FLAGS]) {
1540                 bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1541                 cb->args[2] = bf.value;
1542         }
1543
1544         if (tb[TCA_ROOT_TIME_DELTA]) {
1545                 msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1546         }
1547
1548         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1549                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1550         if (!nlh)
1551                 goto out_module_put;
1552
1553         if (msecs_since)
1554                 jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1555
1556         t = nlmsg_data(nlh);
1557         t->tca_family = AF_UNSPEC;
1558         t->tca__pad1 = 0;
1559         t->tca__pad2 = 0;
1560         cb->args[3] = jiffy_since;
1561         count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1562         if (!count_attr)
1563                 goto out_module_put;
1564
1565         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1566         if (nest == NULL)
1567                 goto out_module_put;
1568
1569         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1570         if (ret < 0)
1571                 goto out_module_put;
1572
1573         if (ret > 0) {
1574                 nla_nest_end(skb, nest);
1575                 ret = skb->len;
1576                 act_count = cb->args[1];
1577                 memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1578                 cb->args[1] = 0;
1579         } else
1580                 nlmsg_trim(skb, b);
1581
1582         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1583         if (NETLINK_CB(cb->skb).portid && ret)
1584                 nlh->nlmsg_flags |= NLM_F_MULTI;
1585         module_put(a_o->owner);
1586         return skb->len;
1587
1588 out_module_put:
1589         module_put(a_o->owner);
1590         nlmsg_trim(skb, b);
1591         return skb->len;
1592 }
1593
1594 static int __init tc_action_init(void)
1595 {
1596         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1597         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1598         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1599                       0);
1600
1601         return 0;
1602 }
1603
1604 subsys_initcall(tc_action_init);